"[B]elief is the death of intelligence. As soon as one believes a doctrine of any sort, or assumes certitude, one stops thinking about that aspect of existence." - Robert Anton Wilson
"If you go into any party or place where people conversationally interact with one another, you will find that half the energy is spent in trying to convince the other that you have the right idea." - Ernst von Glasersfeld
In the social sciences, something that I am well acquainted in as I hold my BA in Political Science and study toward an MA in Media and Communication, it becomes apparent that the ideas that construct the landscape of debate are hypotheses with no extensional, definitive answer. Politics is no more a science than literature, which is no more a science than religion - it is purely the domain of human agency. No scientific test can answer "Will this legislation improve society?" since it is by and large an unanswerable question. Even as our entire existence relies upon chance, uncertainty and probability we as humans never fail in our capacity to believe in perfect exactitude within our own thinking.
Rigid, inflexible thinking has produced much of the horrors of the human age. Dogmatic, two-valued (i.e., right vs. wrong, good vs. bad) thinking has invariably produced the Crusades, the Holocaust and other unimaginable terrors. Atheists invariably turn their ire toward religion as causing these ills and many more. Religionists believe that Atheists will lead us toward a lawless, immoral society due to their non-belief or disputation of a God.
"Is there a God" is, at this present time, an unanswerable question, much like the question of "What does the dark side of the moon look like" until the invention of lunar spaceflight. There is no test, no measuring device, no real way of knowing definitively either way. In my estimation, there is a high probability of the non-existence of a God, but this is my own rationally-derived guess based on my own ideas, my own studies and etc. I can no more prove that God exists than saying that Heavy Metal is the greatest music ever created.
I can agree with the assertion that religion and the Bible is not the word of (a) God; it did not appear spontaneously - it was written by humans for consumption by other humans. The Catholic Church is administered by humans and was created for the benefit (and detriment) of humans.
Despite the empirical evidence that religion is the sole domain of humans without aid from divine intervention, it does not absolutely disprove an existence of a God, it merely confirms that humans conceive a creator in these certain images (Jesus, Buddha, Allah etc.) which has been widely accepted (or foisted upon them) by others. The Christian model of God differs from the Jewish model and the Islamic model and in the absence of any evidence to the contrary or to the affirmative, all models are equally valid.
Leaving the debate as to whether religion "poisons all things" or subjugates certain peoples, it does force people into Aristotelian, two-valued thinking if they so choose to believe all premises offered by their chosen religion. Humans in their own agency have the choice to follow a religion - irrespective of the consequences of its renunciation or not - just as much as they have a choice in which football team to favor.
Telling someone they are wrong in matters they themselves cannot prove does not confirm their rightness. Karl Popper, the philosopher accused Theism of being "worse than an open admission of failure, for it created the impression that an ultimate explanation had been reached." Now (some strands of) Atheism offer the same ultimate explanation, mostly through the works of Charles Darwin and his theory of evolution.
The current scientific paradigm that prevails today is that this evolutionary process is the explanation for humanity's current form. However, a scientist would also concede the point that Darwin's theory could one day be invalidated by a superior conjecture and hypothesis as our technology grows. So even Darwin's theory has a very high probability of being true-to-fact and true-to-observation, but cannot be deemed 100% correct.
Of course, the virtue of being content in verisimilitude is that it relieves a lot of mental pressure on being totally "right" all the time. One can sit back and explore his own universe and marvel at its complexity. Then again, you could tell me I'm full of shit - and that's fair enough too!